5,278 research outputs found
Signals of new physics in global event properties in pp collisions in the TeV energy domain: rapidity intervals
The study of possible new physics signals in global event properties in pp
collisions in the TeV energy domain is extended from full phase-space to
rapidity intervals experimentally accessible at LHC. The elbow structure in the
total multiplicity distribution predicted in full phase-space is clearly
present also in restricted rapidity intervals, leading to very strong charged
particle correlations. It is also found that energy densities comparable to
those reached in heavy ion collisions at RHIC could be attained in pp
collisions at LHC.Comment: 10 pages, 4 figure
On signals of new physics in global event properties in pp collisions in the TeV energy domain
In the framework of the weighted superposition mechanism of different classes
of minimum bias events (or substructures), described by the negative binomial
multiplicity distribution, in possible scenarios for pp collisions in the TeV
energy domain, we explore global properties of an eventual new class of events,
characterised by high hadron and clan densities, to be added to the soft
(without minijets) and semihard (with minijets) ones. It turns out that the
main signal of the mentioned new physical expectations at 14 TeV c.m. energy
would be an ``elbow structure'' in the tail of the total charged particle
multiplicity distribution in complete disagreement with the second shoulder
structure predicted by Pythia Monte Carlo calculations: a challenging problem
for new experimental work.Comment: 14 pages, 6 ps figures include
On Statistical Mechanics Developments of Clan Concept in Multiparticle Production
Clan concept has been introduced in multiparticle dynamics in order to
interpret the wide occurrence of negative binomial (NB) regularity in n-charged
particle multiplicity distributions (MDs) in various high energy collisions.
The centrality of clan concept led to the attempt to justify its occurrence
within a statistical model of clan formation and evolution. In this framework
all thermodynamical potentials have been explicitly calculated in terms of NB
parameters. Interestingly it was found that NB parameter k corresponds to the
one particle canonical partition function. The goal of this paper is to explore
a possible temperature and volume dependence of parameter k in various classes
of events in high energy hadron-hadron collisions. It is shown that the
existence of a phase transition at parton level from the ideal clan gas
associated to the semihard component with k>1 to the ideal clan gas of the hard
component with k<1 implies a discontinuity in the average number of particles
at hadron level.Comment: 20 pages, latex, no figures; v2: the description of the framework has
been considerably expanded, and the main body has been reorganized for
clarit
Clan structure analysis and new physics signals in pp collisions at LHC
The study of possible new physics signals in global event properties in pp
collisions in full phase space and in rapidity intervals accessible at LHC is
presented. The main characteristic is the presence of an elbow structure in
final charged particle MD's in addition to the shoulder observed at lower c.m.
energies.Comment: 9 pages, talk given at Focus on Multiplicity (Bari, Italy, June 2004
Possible scenarios for soft and semi-hard components structure in central hadron-hadron collisions in the TeV region
Possible scenarios in hh collisions in the TeV regions are discussed in full
phase space. It is shown that at such high energies one should expect strong
KNO scaling violation and a ln(s) increase of the average charged multiplicity
of the semi-hard component, resulting in a huge mini-jet production.Comment: 20 pages, 9 PS figures included, LaTeX2e with AMSmath, epsfi
Scenarios for multiplicity distributions in pp collisions in the TeV energy region
Possible scenarios based on available experimental data and phenomenological
knowledge of the GeV energy region are extended to the TeV energy region in the
framework of the weighted superposition mechanism of soft and semi-hard events.
KNO scaling violations, forward-backward multiplicity correlations, Hq vs. q
oscillations and shoulder structures are discussed.Comment: 10 pages, 10 figures, talk given at "Focus on Multiplicity" (Bari,
Italy, June 2004
Power series distributions in clan structure analysis: new observables in strong interactions
We present a new thermodynamical approach to multiparticle production in high
energy hadronic interactions, making use of the formalism of infinitely
divisible power series distributions. This approach allows us to define new
observables, linked to the system fugacity, which characterise different
classes of events.Comment: 9 pages, 2 figures, talk presented by R. Ugoccioni at "Correlations
and Fluctuations 2002", Crete, Greece, 8-15 June 200
Forward-backward multiplicity correlations in e+e- annihilation and pp collisions and the weighted superposition mechanism
Forward-backward multiplicity correlations in symmetric collisions are
calculated independently of the detailed form of the corresponding multiplicity
distribution. Applications of these calculations to e+e- annihilation and ppbar
collisions confirm the existence of the weighted superposition mechanism of
different classes of substructures or components. When applied to ppbar
collisions in particular, clan concept and its particle leakage from one
hemisphere to the opposite one become of fundamental importance. The increase
with c.m. energy of the correlation strength as well as the behaviour of the
average number of backward particles vs. the number of forward particles are
correctly reproduced.Comment: 8 pages, 2 figures, talk presented by A. Giovannini at "Correlations
and Fluctuations 2002", Crete, Greece, 8-15 June 200
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